Process of producing carbon tetrachlorid.



W. P. DOERFLINGER'. PROCESS OF PRODUCING CARBON TETRAGHLORID.

I APPLICATION FILED MAY 19, 1909.

992,551, v PatentedMay 16,1911.

WITNESSES IIVI/ENTOR A TTOR/VEY UNITED STATES PATENT OFFICE.

wILLIAnt r. IDOERFLINGER, OF' NEW YORK, N.

PROCESS OF PRODUCING CARBON TETRACIiLoRID.

Specification of Letters Patent. Patented May 16, 1911 Application filed May 19', 1909. Serial No. 497,027.

To all whom it may ainccm:

Be itknown that I, VVILIJAM F. DoER- FLINGER. a citizen of the United States, and a. resident of New York city, borough of B1'(-)Oll VTl. in the county of Kings and State of New York, have invented certain new and useful Improvements in Processes of Producing Carbon Tetrachlorid, of which the following is a specification.

Myinvention relates to an improved -i method of producing carbon-tetrachlorid from carbon disulfid and chlorin. 1 In conducting my process I employ liquid absorbing agent, capable of taking up chlorin to form a chlorinating solution which can be made to react wlthcarbon dlsulfid, converting it to carbon tetrachlorid and forming a liquid product capable of absorbing chlorin to form a chlorinating solution.

.This liquid medium I will refer to hereafter as the absorbing liquid. It may be of such nature that it merely dissolves chlorin to form a solution in which the chlorin absorbed is not chemically combined; or it may be of such nature that it dissolves chlorincombining wit-h it-to form a wealr chemical compound which reacts with carbon disulfid directly or can be made to do so by suitable means as by theacti-on of a catalytic agent. As specific absorbing liquids which may be employed I mention, by way of example, carbon tctrachlorid, or sulfur chlorid, or a mixture of carbon tetrachloridand sulfur chlorid. Starting with such an absorbing liquid I subject it to the action of chlorin whereby a chlorinating' agent is formed, I then admix carbon disuL fid and cause it to react producing carbon tetrachlorid and forming a liquid absorbing agent. This is subjected to the action of chlorin forming a chlorinating solution, which is admixed with carbon disulfid and caused to react with it producing more carbon tetrachlorid and formin a liquid absorbing agent. The 'cycle is repeated'as often as desired, absorbing more chlorin,

, admixing and converting more carbon disullid and so on, producing more and more carbon tetrachlorid. From-,time'to time a portion of the liquid may be withdrawn and the carbon tetrachlorid separated as by fractional distillation. Heat .is evolved in the conversion of the arbon disulfid to carbon 7 tetrachlorid and generally also, though in less amount in the absorption of chlorin. to form 'chlorinating agent. This heat I abstract at some and prefer to abstract itafter the conversion of carbon disulfid to carbon tetrachlorid has taken place and before absorbing more chlorin. I prefer to so conduct the operation that at no point in the cycle does the point or points in the cycle,

temperature rise high enough to cause the liquid at that point to boil. This may be accomplished by suitable cooling and regulatmg the amount'of chlorin and carbon disulfid introduced in each cycle. I prefer to induce combination by circulating the mixture of carbon disulfid and chlorinating agent incontact with an extended surface of a catalytic agent. v I prefer to start with a mixture of carbon tetrachlorid and disulfur dichlorid containing .about equal molecular proportions of each, at about atmospheric temperature or below. This mixture is brought into con tact with chlorin, whereby a solution of chlorin in carbon tetrachlorid and sulfur chlorin as a gas, either pure or as a constituent of a gaseous mixture; but I may also apply it as liquid chlorin. The mixture of carbon tetrachlorid and sulfur chlorid I employ in excess, and prefer to use it in such proportions that there is about 100 parts of the original mixture to each part of chlorin absorbed. It is, however, possible to op'eratesuccessfully throughout wide limits.

.chlorid is formed. In general I apply the a soluble catalyzer is employed it may be dissolved in the 'mixtureof carbon tetrachlorid and sulfur chlorid at the start. While I prefer to use the carbon disulfid in amount chemically equivalent to the dissolved ch10 rin or chlorin weakly held chemically, it

may be mixed in less or greater amount. If used in equivalent amount there results a mixture of carbon tetrachlorid and sulfur chlorid in increased amount. If in less amount the mixture willstill contain dissolved chlorin'or chlorin weakly held chemi-.

cally, z. 6., as monosulfur dichlorid. If in or device. The chlorin solution overflowgreater amount the resulting mixture may ing at D passes into a mixer J, wherein carcontain free sulfur or carbon-sulfur-chlorin bon disulfid .is admixed. The rate of carcompounds. Heat is evolved in the combinabon disulfid supply is controlled .by a cock tion, which I prefer to abstract either at the K. It is admitted in about the proportion 70 pointwhere the reaction occurs or at a subof one molecule of carbon disulfid to six sequent stage. I then repeat the'entire cycle atoms of dissolved chlorin 6., for each 100 of operations, absorb more chlorin, admiX lbs, of mixture entering at 1) containing 1 more carbon disulfid, induce combination, lb. of absorbed chlorin, there is added about cool, and so on, as often as desired,-pr0duc- .36 lbs. of carbon disulfid). The addition 75 ing carbon I tetraehlorid and Sul ur Chlorid of carbon disulfid is continuous and the rate in ever increasing amount. I As the amount of addition controlled by regulating the increases a portion is withdrawn from time cock K. The mixture now containing ad-. to time and the carbon tetrachlorid sepamixed carbon disulfid overflows continuously rated in a suitable manner, for instance, by f om the mixer by way of the overflow pipe 80 fractional distillation. The residue consist- L i t th onv rte M, Any vapor formed g argely of SU Chlorid m y n be in the mixer J passes by a pipe N to a conutilized in the manufacture of useful proddenser 0 h r th va rs are condensed ucts, as in the manufacture of carbon tetrad fl b k b th i P i t th con- ChlOI'ld. by kIlOWIl-IIlGthOdS. I findthat in verter The converter M consists of a '85 general the CaI'bOII r hl ri P O series of compartments loosely filled with from the residue y the on methods: c011-v pieces of iron, for instance, sheet metal cliptains considerable amounts of carbon disuli d so a an d that th liquid enters fid a Prefer to iIitmduPe it back into at the bottomof each compartment and over- -rny main process in pr0p0rt10n C SP flows at the top to the bottom of the next.

g t0 its Carbon dlslllfiq/colltent, whereby During its passage the iron acts catalytically it is readily converted into carbon tetrachlod th carbon di lfid i converted t rid free o Carbon fl f bon tetrachlorid and sulfur chlorid. Con- In p i g y mventlonl prefer to siderable heat is evolved in the converter;

30 Operate fi-S f0110 WS, referel'lce g to with the mixture entering at 15 degrees cen-. he accomp nying dra ing 1n q tigrade the temperature rises to around 40 Whelf in S l app t is r pr 111 degrees centigrade at the exit. Any vapor a conventional manner; it being understood f d in M passes byway of the pipes Q that the apparatus may be gr at y var ed and N to the condenser Q where it is con- 35 Without d p rt ng fi the Spirit Of y densed and flows back into the converter M.

vention. From a reservoir A a mixture of The liquid after passing through the vadisulfur dichlorid and carbon tetrachlorid rious' compartments of the converter M containing about 53% carbon tetrachlorid fi ll v fl s th h th i e R to the and Sulfur l d, at about atmoscooler S where it is cooled by contact with 40 pheric temperature, is allowed to flow by the cooling coils T, through which cold way of a pipe into, a chlorinator C, the rate water, brine, or cold carbon tetrachlorid or of the flow being controlled by a 000k 13- other'cooling liquid is circulated. The tem- In the chlorinator it flows slowly from one perature of the cooling liquid, rate of flow, end to the other finally overflowing at the and surfaceof the coils is so regulated that overflow pipe D. During its passage the mixture finally overflows by the over- 0 through the chlorinator it meets and abflow pipe U at ab t atm heric temperasorbs a current of chlorin, entering at E, ture. From U the liquid'fiows into the resaid chlorin flowing in the opposite direcceiver V, whence it is pumped by the pump tion toward the outlet F. The supply of W to the reservoir A to begin its round 50 chlorin and the rate of flow I so regulate anew.

' I that the mixture overflowing at D contains The reason for using the specific mixture about one percent. of chlorin dissolved or of sulfur chlorid and carbon tetrachlorid is weakly held chemically. Any residual non because it is a very eflicient chlorin absorbabsorbable gas escapes at F, whence it ing agent, which takes up chlorin with great 55 passes to a condenser G, where entrained avidity. The mixture also heats uponly vapor of carbon tetrachlorid is condensed slightly in taking up chlorin, and has very and runs back'through the pipe H into the little action upon structural material. The chlorinator C. The chlorin entering at E solution of chlorin in this medium reacts maybe under pressure. or suction. In ge'nwith carbon disulfid to form ('01, very {Leral there is little heat evolved in the chlorin readily in the presence of a suitable cataabsorption, and the mixture leaves the chlorlytic agent, with minimum formation of ininator at only slightly increased temperatermediate compounds. The solution also tures. The chlorlnator may also be conacts very slightly, if at all, upon carbon distructed on the principle of the well known sulfid in the absence of a catalytic agent.

65 Lungs plate tower, or other absorbing tower This is a considerable advantage if carbon disulfid is occasionally fed a little too rap- -idly, since in this case there is little tendency to heat up unduly, in the absorbing which are brought about in it since uncoucompartments, where undue evolution of heat would be undesirable. Finally, it is not changed in composition by the reactions and S Cl are in the same relative amount in the mixture in which they are produced by the series of reactions, z'. 6., 1 001 to ,1 S 01 and it is only necessary to withdraw a portion to maintain the mixture c011- stant in amount and composition. The mixture of a little CS and the solution of Cl in (3C1 and 01 also has a comparatively high boiling point.

- practically automatic. It is easily con- Asthe amount of-carbontetrachlorid and sulfur chlorid accumulates, a portion overflows by the overflow pipe X into a stock tank Y. Carbon tetrachlorid of a very pure form is readily separated from the stock tank mixture. The sulfur chlorid after separation ismarketed as such or otherwise uilized. 4

The process is conducted in a continuous manner and with very little labor, as it is trolled by watching the temperature in the converter M and in the chlorinator C. With a constant supply of. chlorin, if the temperature tends to rise too high in the converter, the carbon disulfid supply is reduced or the rate of supply of liquid from the reservoir is increased by further opening the cock B. If the temperature in the converter drops it is in general not prejudicial sincewith the large excess of sulfur chlorid and large surface of iron exposed,conversion is induced (though at a slower rate)' even atordinary temperature. The temperature may, however, be raised either by decreasing the flow of liquid from the reservoir, or by increasing the supply of carbon Y is very 'easy.

disulfid. The appearance of the liquid at various points of the system and determination ofthepercentage of the various constituents assists in-the intelligent control of the process.

The separation of very pure carbon tetrachlorid from the stock tank Y mixture My preferred method is as follows: A portion of the stock tank mixture is heated and the carbon tetrachlorid fractionally distilled off" and condensed.

The vapors of carbon tetrachlorid may still contain a little sulfur chlorid, in practice about 1%.

The condensate flows into an aqueous solution of caustic soda or other soluble caustic alkali, which is kept in continuous agitation. The caustic soda decomposes and combines with the sulfur chlorid.

After the distillation is finished agitation is continued for a few hoursto insure complete combination, then the liquid is allowed to settle, layers by gravity and the up- I solution of caustic soda or other soluble caustic alkali, or a solution of a soluble caustic alkali to which a compound of a metal forn'iiri'g insoluble sul fid with hydrogen sulfid, stable under the conditions, such, as zinc sulfate haS been added. I then distil off the carbon tetrachlorid and separate it from the Water which passes over with it by gravity.

The equations illustrating the preferred method of operatin as described in the specifications are as ollows:

This is the reaction which occurs in the chlorinator. It is probable, however, that not, all the chlorin unites to form SCl a portion being merely physically dissolved.

-This is the reaction which occurs in the converter.

COL and one S CI is withdrawn, the remaining 90CCl and 908 01 going back to the chlorinator to begin another cycle.

The preferred temperature is atmospheric or a little lower at the entrance to the absorber, say 12 C. At the exit of the absorber slightly higher, say 15 (1., in the converter between the entering temperature and the boiling point of the mixture, pref- Of I the 91001,+91S.01 .one.

erably leaving the converter at about 40 C.

though it may be considerably higher.

It is preferred to so operate that theliquid leaving the chlorinator is red in color and yellow or reddish yellow, leaving the converter. The percentage composition leaving the chlorinator should show about one per cent. chlorin in excess of thathecessary to combine with all the sulfur to form S 01 and with all the carbon to form C01, for

example: CO1 52.47%, S Cl 46.53%, G1

1.00%. Leaving the converter it is preferred that the mixture consist entirely of CO1, and S,Cl,,'z'. e. no CS CSCI $01,, or free chlorin, for example: CO1; 53.00, S 01 47.00.

Having now described my invention, what I. claim and desire to protect by Letters Patent is 1. The process of producing carbon tetraand absorbing chlorin in it, admixing car bon disulfid in amount about equivalent to the chlorin absorbed and causing it to react with the chlorin absorbed forming carbon tetrachlorid by means of a catalytic agent.

2. In the production of carbon tetrachlorid the steps which consist in absorbing chlorin in a liquid medium comprising carbon tetrachlorid and disulfur dichlorid, admixing carbon disulfid and circulating the liquid mixture in contact with an extended surface of a catalytic agent at a temperature below 45 C.

3. The process, of producing carbon tetrachlorid, which consists in absorbing chlorin in an excess of a liquid medium comprising sulfur chlorid and carbon tetrachlorid, admixing carbon disulfid and causing it to react with the chlorin absorbed by means of acatalytic agent forming carbon tetrachlon'd. r 4

4. The process of producing carbon tetr'achlorid, which consists in absorbing chlorin -in an excess of a liquid medium comprising sulfur chlorid andcarbon tetrachlorid, admixing carbon disulfid. and causing it to reactwith the chlorin absorbed at a temperature below the boiling point of the mixture by'means of' a catalytic agent forming car 'bon tetrachlorid.

a The process of'producing carbon tetrachlorid which consists in forming a chlorinating solution by subjecting a chlorin absorbing liquid to the action of chlorin, admixing carbon disulfid and causing it to react with the chlorinating solution, whereby carbon tetrachlorid is produced, and a liquid chlorin absorbing agent is formed, subjecting the product to the action of chlorin forming a chlorin'ating solution, admixing carbon disulfid and causing it to react with the chlorinating solution whereby carbon tetrachlorid is produced and a liquid chlorin absorbing agent is formed. 6. The process of producing carbon tetrachlorid, which consists in forming a chlorinating solution by subjecting a chlorin absorbing liquid to the action of chlorin, ad-

mixing carbon disulfid and causing it to react with the chlorin absorbed, whereby carbon tetrachlorid is produced, and a liquid chlorin absorbing agent is formed, abstracting the heat evolved by the reaction, and subjecting the product to the action of chlorin forming a chlorinating solution, admixing carbon disulfid and causing it to react with the chlorin absorbed whereby-carbon tetrachlorid is produced and a liquid chlorin absorbing agent is formed.

7 The cyclic process of producing carbon tetrachlorid, which consists in absorbing chlorin in a emixture comprising carbon tetrachlorid and chlorid of sulfur admixing carbon disulfid and causing its combination to form a solution containing an increased amount of v carbon tetrachlorid, absorbing chlorin in this product, admixing carbon disulfid, and causing its combination to form solution containing an in'creased'amount of carbon tetrachlorid.

8. The process of producing carbon tetrachlorid which consists in the alternate absorption of chlorin in an excess of liquid medium comprising carbon tetrachlorid and an excess of sulfur chlorid, and the admixture of carbon disulfid which 1s made to react with the chlorin absorbed to form carbon ture of carbon disulfid which is made to react with the chlorin absorbed to form carbon tetrachlorid and abstracting the heat evolved by the reaction. v

' 10. A process for producing carbon tetraclilorid, which consists in alternately abthe temperature throughout below the boiling point of the mixture.

' n testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

\VILLIAM F. DOERFLINGER.

\Vitnesses FRANK E. RAFFMAN,

C. G. HEYLMU'RM sorbing chlorin in a liquid medium, compris- 

